1. Field of the Invention
The invention relates to a brake control apparatus for a vehicle and a brake control method, that control the braking force applied to wheels provided on the vehicle.
2. Description of the Related Art
A wheel slip control apparatus that performs a brake control for restraining a drive wheel slip during acceleration of the vehicle, on the basis of the estimated temperature of a brake pad estimated by a brake pad temperature estimation device has been known (e.g., see Japanese Patent Application Publication No. JP-A-7-156780). In the brake pad temperature estimation, the temperature gains of the brake pad caused at the time of braking and at the time of brake control, and the temperature decline caused when neither the braking nor the brake control is performed are worked out. From the temperature gains and the temperature decline, the temperature of the brake pad is estimated.
In addition, an electrical control apparatus that determines a friction coefficient between a pad and a rotor following continuous changes of the temperature detected by temperature detection means, and that determines a target value of the brake oil pressure on the basis of the friction coefficient and the pedal depression force has been known (e.g., see Japanese Patent Application Publication No. JP-A-5-92760). Furthermore, a vehicular brake apparatus that performs a control such that the pressure of a working fluid supplied from an air tank to a brake main body upon output from a temperature sensor that detects a change in the surface temperature of friction members of the brake main body is corrected in accordance with changes in the friction coefficient of the friction members of the brake main body is known (e.g., see Japanese Patent Application Publication No. JP-A-3-7644).
Since the temperature of a friction member and the friction coefficient has a certain relationship, the braking force generated by friction fluctuates in accordance with the temperature of the friction member. Therefore, adjustment of braking force in accordance with the temperature of a friction member has been performed in the related art. Hence, in the case where an estimated value of the temperature of a friction member of a brake is used, the estimation accuracy of the temperature may decline due to occurrence of an abnormality, external disturbance, etc. If the estimation accuracy declines, there is a likelihood of the estimated temperature deviating from the actual temperature of a friction member. If the estimated temperature deviates from the actual temperature of the friction member, it becomes difficult to sufficiently restrain the fluctuations of the braking force which are caused by temperature changes of the friction member.